The Environmental Protection Agency, acknowledging developing awareness of Reagan administration policies, has ended a two-year dispute by granting the Coors Beer Company permission to build a giant brewery a mile from Virginia's Shenandoah National Park.

With the EPA permit, Joseph Coors -- whose conservative views are similar to those of President-elect Ronald Reagan and who is a close political ally of Interior Secretary-designate James G. Watt -- has cleared the last major hurdle in his attempt to break into the East Coast beer market in a big way by establishing a second manufacturing plant.

Called by one EPA official "one of the cleanest plants in the country," the proposed brewery in other eyes is the harbinger of a new, more relaxed government attitude toward industry's effects on air and water quality.

"We feel this will come right in line with what Reagan is looking for," said another EPA spokesman. "Everyone in EPA is aware of where things stand now."

Since Coors announced in January 1979 in had selected land near Harrisonburg in rural Rockingham County as a site for its $200 million plant, the proposal has stirred alarm and resentment among some Virginians, who fear the area will lose its relatively clean air and country flavor.

The promise of nearly 2,000 jobs from the plant alone, with a possible 2,000 additional jobs from supporting industries, has encouraged equally strong support from local leaders who welcome the promised revenues.

"The coming of an industry of this size into a small community like ours will just start us down a path that many other troubled towns have faced before," said one local activist opposed to the plant. "It's so attractive and seductive, people can't say no to it. But it's like a teen-age girl who wants to have a baby. She won't really know what it's like until she has it." w

Construction of the plant probably will begin in 1983, though Coors is "keeping its options open," a company spokesman said, with another site in Tennessee.

Some religious leaders in the area, heavily populated by Mennonites of German descent, argued against the brewery on moral grounds. It was opposed by the local Farm Bureau as a threat to hundreds of acres of valuable farmland.

Even some local leaders who favor Coors have expressed reservations that the ultimate impact of additional population and automobile traffic generated by the facility may be more than anyone bargained for. But others have worn Coors baseball caps and lapel buttons to express their all-out approval.

One of the brewery's most vigorous opponents is Robert Jacobsen, director of the Shenandoah National Park whose border the plant would share. Jacobsen said yesterday he still fears the effects of emissions from the brewery on the park's flora. "There's no question," Jacobsen said, "that [Coors] will add to the pollutant loading of the air."

Plant emissions of sulfur dioxide, he said, will aggravate the effects of ozone, which already is killing some of the park's trees and sterilizing others. Jacobsen also expressed concern that smoke from the plant would obsure the park's vistas, which draw thousands of visitors annually.

Like many of his counterparts at EPA, however, Jacobsen said he was satisfied that if construction of the plant could not be stopped, at least its foreseeable impact on the environment will have been minimized by required emission control measures.

"When they first proposed a brewery here in the valley, it was one that would have emitted an unacceptable amount of pollutants," Jacobsen said. "Through long meetings, the original concept was altered to one that falls within the limits prescribed by Congress."

Most of those changes, officials said, were made before the November elections.

"This had nothing to do with the elections," said EPA attorney John Cooper. "This is not a sellout to Mr. Watt."

Among the changes was a reduction in the plant's size, officials said. Originally planned to be capable of making 25 million gallons of the brew annually, plans now call for a facility with a 10-million-gallon capacity.

EPA officials also objected to the use of locally available 2 percent, low-sulfur coal in the plant. Coors eventually bent to federal wishes, company officials said, by designing "unusual" emission controls to trap pollutants before they leave the stacks.

"We agreed to meet their requirements," said Coors attorney Henry Clark. "They required us to give them in minute detail the data they felt they needed to base a decision on."

EPA officials said emissions from the plant that might detract from the nearby park will be almost nonexistent. "We're being pushed even harder [than under the Carter administration] to work with industry to come up with ways to contain pollution that are more cost effective," said an EPA spokesman.

Much of the original outrage stirred by the proposed brewery has since dissolved into private grumbling, residents said yesterday. Attention has lately turned to the more precise tasks of monitoring the brewery's possible effects on air and the Shenandoah River, already ailing from industrial pollution.

"It's surprising the number of people who aren't talking about it," said Ruth Stolzfus, a local attorney and cofounder of the Valley Environmental Council. "But if they're coming in here anyway, we ought to make sure that they don't kill a river that's already sick."